The purpose of this project is to study the chemistry and biochemistry of biogenic amines, their amino acid precursors and transformation products. The areas of specific interest are: 1) the immunolocalization of catechol-0-methyltransferase (COMT), monoamine oxidase (MAO) in malignant and normal human and rodent tissues. 2) The effect of substitution of fluorine on the aromatic ring amines. 3) The mechanism of toxicity and leukocytopoiesis of 2-fluorohistidine in normal and leukemic mice, and the metabolism and incorporation into protein of 2-fluorohistidine in vivo and in vitro.